At the University of California, San Diego, researchers have 3D printed tiny “microfish” that have propulsion mechanism, navigation, and even detoxification capabilities that may allow them to swim through blood and maybe even deliver targeted drug therapy. The hydrogel microfish are manufactured using microscale continuous ­optical printing (μCOP) which permits the creation of complicated shapes and multiple functional areas.

On the back of the microfish there’s a pouch with platinum nanoparticles that react with hydrogen peroxide to propel the fish forward, while on the front there’s a space filled with iron oxide nanoparticles that can be pulled on with a magnet to guide the fish in a particular direction.

The body of the fish was infused with polydiacetylene (PDA) nanoparticles that are able to inactivate certain toxins. Interestingly, these nanoparticles emit a fluorescent glow when reacting with toxins, allowing their activity to be tracked and pointing to areas of high toxicity.